From ee78fbef0d19e74fed0a8e20f6ad896db7c75aa9 Mon Sep 17 00:00:00 2001
From: paxx12 <245230251+paxx12@users.noreply.github.com>
Date: Mon, 30 Mar 2026 16:37:24 +0200
Subject: [PATCH] Fix NTAG UID for multi-cascade anti-collision

In ISO 14443-3 anti-collision, multi-byte UIDs (7 or 10 bytes) span
multiple cascade levels. Intermediate levels prefix UID parts with a
cascade tag byte (0x88) that must be excluded from the final UID.

The FM175xx driver was appending the full `UID_part` at every level,
including the cascade tag of intermediate levels, yielding a corrupt UID.

Strip the first byte from `UID_part` for all levels except the last so
the assembled UID contains only the actual tag bytes.
---
 .../local/share/openrfid/02-fix-ntag-uid.patch   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 overlays/firmware-extended/31-openrfid/patches/usr/local/share/openrfid/02-fix-ntag-uid.patch

diff --git a/overlays/firmware-extended/31-openrfid/patches/usr/local/share/openrfid/02-fix-ntag-uid.patch b/overlays/firmware-extended/31-openrfid/patches/usr/local/share/openrfid/02-fix-ntag-uid.patch
new file mode 100644
index 00000000..12e761d5
--- /dev/null
+++ b/overlays/firmware-extended/31-openrfid/patches/usr/local/share/openrfid/02-fix-ntag-uid.patch
@@ -0,0 +1,16 @@
+diff --git a/reader/fm175xx/rfid.py b/reader/fm175xx/rfid.py
+index 8e0e877..c860a26 100644
+--- a/reader/fm175xx/rfid.py
++++ b/reader/fm175xx/rfid.py
+@@ -479,7 +479,10 @@ class Fm175xx(MifareClassicReader, MifareUltralightReader):
+                 ret = Constants.FM175XX_CARD_COLL_ERR
+                 break
+
+-            UID += UID_part
++            if level < cascade_level - 1:
++                UID += UID_part[1:]
++            else:
++                UID += UID_part
+             BCC.append(BCC_part)
+
+             (ret, SAK_part) = self.__reader_a_select(level, UID_part, BCC_part)